Intra block copy merge list simplification

A video encoding method comprising:

• receiving raw pixel data for a block of pixels to be encoded as a current block of a current picture of a video into a bitstream, wherein a plurality of spatially adjacent neighboring blocks of the current block are coded before the current block;
• generating a list of merge candidates including intra picture candidates that are associated with motion information referencing pixels in the current picture, the intra picture candidates comprising spatial merge candidates that are associated with the plurality of spatially adjacent neighboring blocks of the current block, the list of merge candidates comprising at most two spatial merge candidates,
• wherein whether a history-based motion vector prediction (HMVP) candidate is included in the list of merge candidates or not is dependent on whether at least one HMVP candidate is available, and whether a default merge candidate is included in the list of merge candidates or not is dependent on a number of the spatial merge candidates and the HMVP candidate in the list of merge candidates;
• selecting a merge candidate from the generated list of merge candidates;
• and
• encoding the current block into the bitstream by using the motion information of the selected merge candidate,
• wherein generating the list of merge candidates comprises determining which merge candidate to include in the list based on a size of the current block.

An electronic apparatus comprising:

• a video decoder circuit configured to perform operations comprising:
• receiving data from a bitstream for a block of pixels to be decoded as a current block of a current picture of a video, wherein a plurality of spatially adjacent neighboring blocks of the current block are coded before the current block;
• generating a list of merge candidates including intra picture candidates that are associated with motion information referencing pixels in the current picture, the intra picture candidates comprising spatial merge candidates that are associated with the plurality of spatially adjacent neighboring blocks of the current block, the list of merge candidates comprising at most two spatial merge candidates,
• wherein whether a history-based motion vector prediction (HMVP) candidate is included in the list of merge candidates or not is dependent on whether at least one HMVP candidate is available, and whether a default merge candidate is included in the list of merge candidates or not is dependent on a number of the spatial merge candidates and the HMVP candidate in the list of merge candidates;
• selecting a merge candidate from the generated list;
• and
• decoding the current block by using the motion information of the selected merge candidate,
• wherein generating the list of merge candidates comprises determining which merge candidate to include in the list based on a size of the current block.

A video decoding method comprising:

• receiving data from a bitstream for a block of pixels to be decoded as a current block of a current picture of a video, wherein a plurality of spatially adjacent neighboring blocks of the current block are coded before the current block;
• performing a merge mode in an intra block copy (IBC) prediction for the current block, comprising:
• generating a list of merge candidates to include merge indices that are associated with spatial merge candidates that are associated with the plurality of the coded spatially adjacent neighboring blocks of the current block, the list of merge candidates comprising at most two spatial merge candidates,
• wherein whether a history-based motion vector prediction (HMVP) candidate is included in the list of merge candidates or not is dependent on whether at least one HMVP candidate is available, and whether a default merge candidate is included in the list of merge candidates or not is dependent on a number of the spatial merge candidates and the HMVP candidate in the list of merge candidates;
• selecting a merge candidate from the generated list of merge candidates;
• and
• decoding the current block by using motion information of the selected merge candidate,
• wherein generating the list of merge candidates comprises determining which merge candidate to include in the list based on a size of the current block.